Share via

NSG - Virtual Flow upgrade

OV, Joel 100 Reputation points
2025-10-14T11:07:26.3833333+00:00

I am looking to upgrade an NSG Flow to Virtual Network Flow. I have identified the NSG flow and have the below questions.

  1. If I migrate using the script provided by Microsoft, will the Storage account, settings be updated and remain the same after the upgradation to Virtual Flow?
  2. What happens to the existing NSG Data on the Blob container?
  3. How do I find the dependency of the NSG flow, like which analytics use it to fetch data from the NSG? What happens of them, would those dependent resources start using the Virtual Flow?
  4. How do I identify the dependencies of the NSG?
Azure Network Watcher
Azure Network Watcher
An Azure service that is used to monitor, diagnose, and gain insights into network performance and health.

1 answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. Priya ranjan Jena 1,510 Reputation points Microsoft External Staff Moderator
    2025-10-14T15:07:38.98+00:00

    Hi OV, Joel,

    Here are the answers for your questions, you can follow below points to understand the proceedings.

    1. Will the Storage Account and Settings Remain the Same After Migration?

    Yes, when you use Microsoft’s migration script, the storage account configuration remains unchanged. The script creates Virtual Network Flow Logs and points them to the same storage account that was used for NSG Flow Logs. This ensures continuity for any downstream processes that read from that storage account.

    Reference link:https://free.blessedness.top/en-us/azure/network-watcher/nsg-flow-logs-migrate

    2.What happens to the existing NSG Data on the Blob container?

    Existing NSG Flow Log data in your Azure Blob Storage is not deleted. It continues to follow the retention policy you configured earlier.

    Even after NSG Flow Logs are retired (Sept 30, 2027), historical data remains in storage until its retention period expires

    Reference link:https://free.blessedness.top/en-us/azure/network-watcher/nsg-flow-logs-overview?tabs=Americas

    3.How do I find the dependency of the NSG flow, like which analytics use it to fetch data from the NSG? What happens of them, would those dependent resources start using the Virtual Flow?

    If you have Traffic Analytics enabled, it currently uses NSG Flow Logs. After migration, you must reconfigure Traffic Analytics to use Virtual Network Flow Logs because it won’t automatically switch.

    • Update Log Analytics workspaces or Traffic Analytics to reference the new flow log type.
    • Modify any custom scripts, dashboards, or pipelines that parse NSG Flow Log schema, as Virtual Network Flow Logs

    4.How do I identify the dependencies of the NSG

    • Azure Resource Graph or CLI: Query for NSG Flow Logs and their associated storage accounts.
    • Check Traffic Analytics: In Network Watcher Traffic Analytics, see which NSGs are sending data.
    • Log Analytics Queries: If you have a Log Analytics workspace, run queries to find which solutions or dashboards are consuming NSG Flow Logs.
    • Azure Migrate Dependency Mapping: For complex environments, tools like Azure Migrate Network Flows Analysis can help visualize dependencies

    Reference link:https://free.blessedness.top/en-us/azure/network-watcher/network-insights-overview

    Hope you find this comment helpful,if yes, please “up-vote” for the information provided , this can be beneficial to community members.

    Kindly let us know if you have any additional questions.

    Thanks

    0 comments

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.